A recent study finds that if you’re extroverted it’s best to continue to be outgoing, on a daily basis. And if you’re an introvert, try a few outgoing behaviors, like calling up an old friend or introducing yourself to someone new at work.

We’ve heard the value of extroverted activity before, but now scientists have confirmed the phenomenon across the globe.

Researchers surveyed students in the U.S., Venezuela, China, the Philippines and Japan. And they measured the students’ personality traits along what’s called the “Big Five”—which is openness, extroversion, agreeableness, conscientiousness and neuroticism. And they found that the subjects reported feeling best on the days when they practiced what is considered extroverted actions—like talking with more people, smiling more often, calling friends.

The study concludes that even though people may live in disparate cultures, individual and comparable personality types exist in those cultures, no matter where you are. Which is perhaps something to smile about.